SQ Decoder

Yesterday, I rescued from the city dump, an imaculate Sony SQA 200 'Decoder'/Amplifier.--It was just sitting there--Well, I couldnt turn that down could I?

Havent powered it up yet, as Im unfamiliar with the SQ format--Googling revealed it was one of the old Quadrophonic systems, relying on phase relationship between L=R to derive a 'Surround' soundfield

Any thoughts............?